Research Methods
BY Sarah Zeidat & Omar Noureldin
Experimental
Description
researcher manipulates a variable under highly controlled conditions to see if this produces any changes in a second variable.
Strengths
allows researchers to detect cause-and-effect relationships.
Limitations
can only be used when it is practical and ethical for researcher to manipulate the antecedent conditions.
Example
Elizabeth Loftus designed this ingenious study. First she had all subjects view a video tape of a car crash. Then one week later she asked the subjects a series of questions about what they saw in the video.
Correlation
Description
nonexperimental, descriptive method. variables are not directly manipulated as experimental method.
Strengths
can be used to determine if there is a relationship between two variables without directly manipulating those variables.
Limitations
is that it does not tell researchers whether or not the relationship is causal. does not, cannot, prove causation.
Example
Ecology, a branch of biology, is the study of the relationships of organisms within their environments. One such relationship is that which exists between predator and prey. Logic would tell us that as the number of prey animals increase so should the number of predators.
Naturalistic Observation
Description
allows researchers to observe behavior in the setting in which it normally occurs rather thanartificial and limited setting of the laboratory
Strengths
naturalistic observation is a type of study classified under broader catagory of field studies; nonexperimental approaches used in the field or in real-life settings.
Limitations
take a great amount of time difficulty of observing behavior without disrupting it . difficulty of coding results in a manner appropriate for statistical analysis.
Example
Volcanic eruptions have played a part in forming the Earth's atmosphere as well as many of its landforms both on land and under water. The geologic record contains evidence of eruptions much larger and explosive than any witnessed and even when it is possible to study an erupting volcano, direct observations are, needless to say, dangerous, and rare.
Survey
Description
does not involve direct observation by a researcher.
Strengths
collecting data on aspects of behavior that are difficult to observe directly .On large number of subjects.
Limitations
relies on a self-report method of data collection. Intentional deception, poor memory, or misunderstanding of the question can contribute to inaccuracies in the data.
Example
A drug use survey was mailed to 1,200 randomly selected Arizona State University students during the Fall Semester of 1985. Information was collected on a variety of drugs, frequency of usage, age at first usage, etc.
Case Study
Description
nonexperimental, descriptive type of study, kept by an outside observer, of an individual or group of individuals.
Strengths
useful when researchers want to get a detailed contextual view of an individual's life or of a particular phenomena.
Limitations
without the controlled conditions of the laboratory, conclusions about cause-and-effect relationships cannot be drawn
Example
Huntington's disease is an inherited neurological disorder, causing progressive loss of muscular control and memory and eventual death. Dr. Nancy Wexler of Columbia University has been one of the main players in an attempt to solve some of the mysteries of this disease.